Field of the Invention
The present invention relates to a developer container, a developing apparatus, a process cartridge, an apparatus main body, and an image forming apparatus. Here, a developing apparatus at least includes a developer bearing member that bears developer. Alternatively, a developing apparatus may also include a frame body for housing developer (developer container), a conveying member for conveying the developer, and the like. A cartridge is a piece of equipment which integrates a plurality of components in an image forming apparatus and which is attachable/detachable to/from a main body of the image forming apparatus. A process cartridge at least includes an image bearing member that bears a developer image. In particular, a cartridge which is obtained by integrating an image bearing member and processing means that acts on the image bearing member is referred to as a process cartridge. An image forming apparatus is an apparatus which forms an image on a recording material (transferred material) and is, more specifically, an image forming apparatus such as a copier, a printer, and a facsimile apparatus using an electrophotographic system or an electrostatic recording system.
Description of the Related Art
Conventionally, an image forming apparatus adopting the electrophotographic system is provided with a developing apparatus which forms a developer image by supplying developer to an electrostatic latent image formed by scanning exposure of an image bearing member. In addition, in recent years, there have been many cases where a developing apparatus, an image bearing member, and processing means (charging member and the like) are integrated as a process cartridge. By integrating a plurality of members as a process cartridge and making the process cartridge attachable/detachable to/from an apparatus main body of an image forming apparatus, maintenance work including replenishing developer can be readily performed.
In such a process cartridge system, when developer runs out, images can be formed once again by having a user replace the cartridge or replenish the developer. Therefore, such an image forming apparatus generally includes means for detecting consumption of developer and notifying the user of a placement timing, or in other words, developer amount detecting means. As an example of such developer amount detecting means, Japanese Patent Application Laid-open No. 2001-117346 proposes a plate antenna system which includes a pair of input-side and output-side electrodes and which detects a developer amount by measuring a capacitance between both electrodes.
In addition, Japanese Patent Application Laid-open No. 2003-248371 and Japanese Patent Application Laid-open No. 2007-121646 propose configurations in which a developer bearing member is regarded as an input-side electrode due to application of an AC bias to the developer bearing member and a capacitance detecting portion as an output-side electrode is provided at a location opposing the developer bearing member in a developing apparatus. All of these documents describe systems which detect a developer amount using a change in capacitance that occurs when an amount of developer between a pair of input and output electrodes changes.